In the context of relational databases, a foreign key is a field, or collection of fields, in one table that uniquely identifies a row of another table. The foreign key is defined in a second table, but refers to a primary key in the first table. Foreign key relationships are typically not represented in the metadata of a relational database management system. In situations where the use of an alias is desired, users of a relational database have to include alias creation statements in Data Manipulation Language (DML) statements when entering statements for managing data of the relational database. Such on-demand alias creation and processing complicates DML statements, making the managing of data more difficult for users.